Polyorganosiloxane, which is a kind of silicone, means a polymer having a siloxane linkage substituted with organic groups as a backbone. As an example, it is produced by polycondensation of an aromatic diol such as bisphenol A and a carbonate precursor such as phosgene, is colorless and odorless, is slow to oxidize, is a hypoallergenic insulator that is stable even at room temperature, and is used as electrics, electronics, automobiles, machinery, medicines, cosmetics, lubricants, adhesives, gaskets, plastic artificial aids and the like.
In addition, it has excellent impact strength, dimensional stability, thermal resistance and transparency, and is applied to a wide range of fields such as exterior materials of electrical and electronic products, automotive parts, construction materials, optical components, and the like. Recently, in order to apply these polycarbonate resins to more various fields, many attempts have been made to obtain desired physical properties by copolymerizing two or more aromatic diols having different structures from each other and introducing units having different structures in a main chain of the polycarbonate.
However, as the application field of the copolycarbonate is expanded, the required level of chemical resistance and flame retardancy of the copolycarbonate are gradually increased. Accordingly, there is a need to develop a copolycarbonate having a novel structure capable of improving the chemical resistance and flame retardancy while maintaining the intrinsic physical properties of the copolycarbonate.